Gait trainer

ABSTRACT

The present invention is a gait therapy device which facilitates the lower extremities particularly the action of flexion at the hip and knee to aid a patient in assisted ambulation, as well as knee, foot and ankle action. The gait trainer apparatus comprises: (a) a moveable frame adapted to move along the ground; (b) at least one motion responsive wheel attached to the frame and adapted to contact the ground and to turn as the frame moves along the ground, and at least one wheel having an offset motion portion having a right side and left side; (c) a left foot attachment, the left foot attachment connected to the left side of the offset motion portion by a flexible or elastic member; and (d) a right foot attachment, the right foot attachment connected to the right side of the offset motion portion by a flexible or elastic member.

FIELD OF INVENTION

The present invention relates to a therapeutic aid, more particularly,the present invention relates to a therapeutic aid for gait trainingthat facilitates hip and knee flexion resulting in forward propulsion.

BACKGROUND OF THE INVENTION

Many disabled persons, particularly children with neurological disordersand chromosomal/genetic disorders such as cerebral palsy have difficultyin learning to walk. However, several types of equipment are availableto provide therapy and training to facilitate walking of such patients.

There are a number of walker type devices which help to support thepatient as he or she is attempting walking, some are wheeled, some aremotorized, some unweight the patient by using upright harnesses.However, problems arise when the disabled individuals are unable toactively facilitate the required hip and knee flexion necessary forappropriate reciprocal strides needed for forward propulsion.

In addition, it is also desirable to be able to provide a gait trainerthat allows the therapist to maintain proper posture while assisting thepatient.

The present invention represents an improvement over prior gait trainersand similar devices, such as those described in the following U.S. Pat.Nos. 5,930,272 and 5,765,323 to Bevilacqua; 5,406,758 to Baum; 5,794,388to Jackman; 5,852,906 to Kuban; 6,550,190 B2 to Ruiz et al.; 6,619,001to Pratt and 6,663,317 B1 to Williams et al., all of which are herebyincorporated hereby by reference.

BRIEF DESCRIPTION OF THE PRESENT INVENTION

It is an object of the present invention to provide a gait therapydevice, which facilitates the lower extremities particularly the actionof flexion at the hip and knee to aid a patient in assisted ambulation,as well as knee, foot and ankle action.

In general terms, the present invention includes a gait trainerapparatus comprising: (a) a moveable frame adapted to move along theground; (b) at least one motion responsive wheel attached to the frameand adapted to contact the ground and to turn as the frame moves alongthe ground, and at least one wheel having an offset motion portionhaving a right side and left side; (c) a left foot attachment, the leftfoot attachment connected to the left side of the offset motion portionby a flexible or elastic member; and (d) a right foot attachment, theright foot attachment connected to the right side of the offset motionportion by a flexible or elastic member. That is, the invention includesan offsetting circular motion device mounted on a mobile frame, theoffsetting circular motion device connected to the lower extremities(such as at the foot, ankle, toes or heels) by an elastic or flexiblemember that allows the foot to be unweighted as it moves along its path,which facilitates hip and knee flexion along with assisting the patientin achieving proper stride motion and length.

The frame may be of any material appropriate to the intended purpose,that being to support a patient while attempting to walk. Thesematerials include metals, plastics and carbon fiber. The framepreferably has a lower portion to which wheels are attached andpreferably an upper portion at a height at or above standing hip heightfor support. Support may be provided by handles for the walker, as wellas a seat, sling, anti-scissoring device or chest prompt for upper bodysupport, as are known in the art.

The motion responsive wheel(s) comprise(s) preferably a first motionresponsive wheel positioned so as to turn in response to the movement ofthe frame along the ground, and a second motion responsive wheelconnected to the first wheel so as to turn in response to the turning ofthe first wheel, the second wheel comprising the offset motion portion.

The gait trainer apparatus of the present invention may have supportwheels on the frame or sliding members adapted to permit the framerespectively to roll or slide across the ground as the patient moves theframe during gait training. Preferably, the mobile frame will have atleast three wheels and preferably at least four wheels to facilitatemovement of the frame along a support surface.

The gait trainer apparatus of the present invention may comprise a seatof the type typically used in gait training devices. These may bemounted on the frame and for example may be similar to a bicycle seat ora sling-type seat. The elastic members may be any member sufficient toprovide an upward and forward motion to the foot as it cycles througheach step. These members may include a material selected from the groupconsisting of springs, elastic polymeric bands, and flexible metalbands. As an alternative, any flexible band or rope material that is ofsufficient strength to transmit the required force from the offsetmotion wheel, regardless of its degree of elasticity, where the abilityof the device to store energy is not of concern.

The left and right attachments may be of any mechanical arrangementrequired to effect connection to the feet, such as an ankle strap, footcuff, shoe fixture or cleat, etc. These connections typically will allowthe forward and upward motion of the device to be transmitted to thefeet as it cycles through each step during use of the device.

In a preferred embodiment, the gait trainer apparatus of the inventioncomprises: (a) a moveable frame adapted to move along the ground, theframe comprising support wheels; (b) motion responsive wheel(s) attachedto the frame and adapted to contact the ground and to turn as the framemoves along the ground, and the motion responsive wheel(s) having anoffset motion portion having a right side and left side, and the motionresponsive wheel(s) comprising a first motion responsive wheelpositioned so as to turn in response to the movement of the frame alongthe ground, and a second motion responsive wheel connected to the firstwheel so as to turn in response to the turning of the first wheel, thesecond wheel comprising the offset motion portion; (c) a left footattachment, the left foot attachment connected to the left side of theoffset motion portion by a flexible or elastic member; and (d) a rightfoot attachment, the right foot attachment connected to the right sideof the offset motion portion by a flexible or elastic member.

It is preferred that the first motion responsive wheel is positionedabove the second motion responsive wheel, and that the first motionresponsive wheel is connected to second motion responsive wheel by abelt. The present invention may also include any other mechanicalarrangement to transfer the motion of a first such wheel to a secondsuch wheel, such as through the use of gears or connecting rods, or evena motor actuated and controlled by movement of the first such wheel,such that the first motion responsive wheel moves in response to themotion of the second motion responsive wheel. It is preferred that thefirst motion responsive wheel is disposed high enough such that theoffset motion pulls the extremity both forward and upward.

In other terms, the gait trainer apparatus of the present invention maybe understood as comprising: (a) a moveable frame adapted to move alongthe ground so as to produce translational movement in a forwarddirection; (b) motion conversion means for converting the translationalmovement in a forward direction to a forward and backward motion; (c) aleft foot attachment, the left foot attachment connected to the motionconversion means by a flexible or elastic member; and (d) a right footattachment, the right foot attachment connected to the motion conversionmeans by a flexible or elastic member.

The motion conversion means may be any mechanical means for causingreciprocating motion to be brought to bear on the feet in response tomovement of the frame. This may be through the use of wheels, rods,gears and the like designed to take energy from the translationalmovement of the frame, or may even be the use of a motor to provide suchreciprocating motion and that is actuated in response to translationalmovement of the frame.

In operation, the frame is moved forward by the patient. The movement ofthe frame causes the motion responsive wheel to move in response. Themotion of the motion responsive wheel causes the offset motion wheel tomove to urge the patient's rearmost foot to be pulled upward and forwardthrough the elastic member connection.

The unweighting of the rearmost foot allows the elastic member connectorto cause the attached foot to be drawn forward so as to result in amovement of the foot along the intended proper gait path. That path endswhen the foot completes the step and returns to contact the ground. Thesubsequent forward propulsion of the moveable frame by the patient whopushes off from that foot that has now moved to the forwardmost positioncauses the cycle to repeat with respect to the other foot, and thereforeallowing for an offsetting of the unweighting of each foot in acontinuous fashion.

Preferably, the offsetting circular motion will be created by thematerial that interconnects a device to a grounded wheel. This may be abelt, series of gears (i.e. arranged to translate the motion of themotion responsive wheel such that the motion of the frame is translatedinto a corresponding upward and forward force that continues through thedesired stride length).

It will also be understood that the width of the connections to theoffset motion wheel will be sized so as to accord with the distancebetween the feet of the user.

Preferably, the diameter (d) of the grounded wheel determines stridelength (I) of the individual patient by ½πd=1. The wheel(s) may be madeto be either interchangeable to vary the desired stride length, or thewheels may be provided with extension portions to increase their outsidediameter to increase the stride length as necessary. These extensionsmay be provided in a kit together with additional motion-transmissivebands as necessary.

Preferably, the flexible/elastic connectors attached to the above thedevice and to the individual's lower extremities, will be made by asemi-rigid material that tolerates force of the offsetting motion, suchas plastic, rubber or metal.

Preferably, the wheels will have a lock/anti-lock mechanism to controlthe direction of gait.

Preferably, the frame may further include optional features such assupport bars in position to be gripped by the hands of a user, rotatinghandlebars to control direction, arm prompts to provide proper upperextremity positioning, seating support system to provide proper pelvicalignment, chest harness for trunk control, and an anti-scissoringdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus generally described the nature of the invention, referencewill now be made to the accompanying drawings showing by way ofillustration a preferred embodiment, and in which:

FIG. 1 is a front perspective view of a gait trainer in accordance withone embodiment of the present invention.

FIG. 2 is a side elevation view of a gait trainer in accordance with oneembodiment of the present invention.

FIG. 3 is a side elevation view of a gait trainer in accordance with oneanother embodiment of the present invention, showing the position of auser of the present invention as a mobility aid in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In view of the foregoing summary, the following describes the preferredembodiment of the present invention, which is presently considered to bethe best mode of the invention.

Referring to FIG. 1, the present invention comprises of a main frame 10which in the illustration is made up of rigid interconnecting tubes. Theframe has lower portion 11 bearing support wheels 14 and upper portion12, the upper portion connected to handles 13.

Mounted on the frame 10 through fork 15 is a motion responsive wheel 16with a bearing rod 17 on either end, which allows for circular motion ofthe motion responsive wheel 16, and when attached to a wheeled frame 10,allows for movement by the walker along a path. The fork may be made tobe removably attachable to a frame, so that the motion transmissiveassembly may be retrofitted onto an existing walker or gait trainer.This may be done through the use of removable fixtures such as screws,Velcro bands, wing nuts or clamps known in the art.

Also mounted on the frame 10 is the offset motion wheel 18, which isattached to the frame 10 by fork 15. This offset motion wheel 18 issupported by fork 17 and connected via a crank bar 19. When the motionresponsive wheel 16 is moved by movement of the frame 10, the motiontransmissive cable or band 20 causes the offset motion wheel 18 to turncorrespondingly. The size of the wheels and the size of the crank baraccordingly may be sized to arrive at a stride length and cyclefrequency. Preferably, the motion responsive wheel 16 and the offsetmotion wheel 18 are the same size, and the crank bar 19 extends to theouter diameter of the offset motion wheel 18, such that thetranslational movement of the frame is correspondingly transferred toachieve the appropriate stride length and cycle frequency of the walker.

Attached to the crank bar 19 on each end are elastic tension bands 21,which attach to the crank bar 19 by any appropriate connection thatallows the elastic tension bands 21 to freely turn, such as plastic tubeportion 23. The elastic tension bands 21 are attached to user's feetthrough any appropriate connection, such as a foot or ankle cuff 22, afixture attached to a shoe or an ankle band otherwise designed totransmit the force to the foot to provide the gait-assisting force.Tension from band 21 causes the unweighting of the user's feet insuccession and the crank bar 19 moves up and around in a circular path.As the crank bar 19 moves 180 degrees around, the user's foot is broughtup and advances forward along the line of the band 21. This offsetmotion of the crank bar 19 and the linear motion of the attached foottransfers the tension onto the other band. This unweights the oppositefoot attached to the other tension band, allowing crank bar 19 to moveup and around in a circular motion causing the same affect as previouslystated.

FIG. 2 shows a side elevation view of the device shown in FIG. 1 withcorresponding number references.

FIG. 3 shows a side elevation view of the device similar to that shownin FIGS. 1 and 2 and using the corresponding numerical references fromthose figures, and shown with an adult-size user 24, and showing theaddition of a sling seat 25 attached to the extensions identified ashandles 13 in FIGS. 1 and 2, a chest prompt 27 and arm prompts 28attached to the upper frame portion of the gait trainer 12.

FIG. 3 also shows a user 24 in position in the gait trainer. This Figureshows how the rearmost foot 30 of the user 24 is brought under an upwardand forward tension by the cooperative action of the offset motion wheel18, crank bar 19 and the elastic band 21 as the user urges the frameforward along direction line 31 and the motion is transmitted throughthe motion responsive wheel 16 to the offset motion wheel 18. As theuser begins a step with the rearmost foot 30, the foot is unweighted andguided forward by action of the device. Typically, the device will beconstructed such that the flexible/elastic connectors pull at an angleof from about 5 to about 45 degrees from the ground.

As this foot moves to the foremost position past the other foot 32, theuser may then urge the frame forward which causes the other foot 32, nowin the rearmost position, to be brought under the same upward andforward tension as the foot 30 originally in the rearmost position, asthe offset motion wheel 18 is cycled though a half turn as indicated bythe formula above.

It will be appreciated that the stride length and the amount of forcebrought to bear on the foot of each user may be accommodated in any ofseveral ways, such as by size adjustments in the diameter of the wheels,the degree of offset (i.e. the length of the vertical portion of thecrank bar 19), the length, material and thickness of the flexible orelastic connectors, or any combination thereof. These types ofadjustments may be made depending upon the size, age and disability ofthe user.

In this regard, the invention may be provided in the form of a kit thatmay contain a number of the motion responsive wheels, motiontransmissive cables or bands, and offset motion wheels of various sizes,crank bars of various widths, and connection members of variousmaterials, lengths and or materials, to be able to assemble theinventive arrangement onto walker frames of any size or architecture. Inthis way, the invention may be arranged for users that have varyingstride length, require additional upward and/or forward motion appliedto the foot, or require more or less resiliency applied to the footthrough the connector members.

The embodiments above are intended to be illustrative and not limiting.Additional embodiments are within the claims. Although the presentinvention has been described with reference to preferred embodiments,workers skilled in the art will recognize that changes may be made inform and detail without departing from the spirit and scope of theinvention.

1. A gait trainer apparatus comprising: (a) a moveable frame adapted tomove along the ground, said frame additionally comprises support wheels;(b) a first motion responsive wheel adapted to contact the ground andpositioned so as to turn in response to the forward movement of saidframe along the ground, and a second motion responsive wheel disposedabove said first motion responsive wheel and connected to said firstmotion responsive wheel so as to turn in response to the turning of saidfirst motion responsive wheel, said first motion responsive wheel isconnected to said second motion responsive wheel by a belt, said secondmotion responsive wheel comprising an offset motion portion, said offsetmotion portion having a right side and left side, said offset motionportion comprising a pair of diametrically opposed cranks; (c) a leftfoot attachment, said left foot attachment connected directly to saidleft side of said offset motion portion by a left connection membercomprising an elastic member; and (d) a right foot attachment, saidright foot attachment connected directly to said right side of saidoffset motion portion by a right connection member comprising an elasticmember, said elastic member each of a length and connected such that, assaid second motion responsive wheel turns, and said frame is moved alongthe ground by a wearer wearing said left and right foot attachments onhis or her respective left and right feet, each of the left and rightconnection members are stretched, as said wearer walks along saidground, the distance between said left and right foot is repetitivelyincreased and decreased in respective alternating fashion, so as toexert a direct spring force urging in alternating fashion said left footand right foot forward and toward said offset motion portion.
 2. A gaittrainer apparatus according to claim 1 wherein said frame additionallycomprises sliding members adapted to permit said frame to slide acrossthe ground.
 3. A gait trainer apparatus according to claim 1 whereinsaid frame additionally comprises a seat.
 4. A gait trainer apparatusaccording to claim 1 wherein said left foot attachment and said rightfoot attachment each comprise a strap.
 5. A gait trainer apparatusaccording to claim 1 wherein said connection elastic members comprise amaterial selected from the group consisting of springs, elasticpolymeric bands, and flexible metal bands, ropes and cords.
 6. A gaittrainer apparatus according to claim 1 wherein said first motionresponsive wheel comprises gear teeth and said second motion responsivewheel comprises gear teeth, and the apparatus comprises a movementconnection between gear teeth of said first motion responsive wheel andsaid gear teeth of said second motion responsive wheel.